Boss PS-2 feedback loop mod question

[bigdolphin]

So basically I just soldered a TRS jack between the output lug of the feedback pot and the pad where the lug is supposed to go. Pedals can go as inserts in the loop, but I noticed the PS-2 will start to oscillate when the pot is set to noon instead of 3 o'clock like it normally does when using pedals in the loop. Otherwise feedback behaves normal. Any ideas on how to solve this?